Music is a pretty strange thing when you think about it. Sure, on one hand, there’s an endless space of creativity and a million different instruments you can use to produce various types of music. But on the other hand, we usually like the same types of songs and harmonies. I’m not talking about the same types of songs you hear on the radio. I’m talking about musical harmony, the relationship between notes played.

Take, for instance, the infamous “four chords” — C, G, A minor and F. Hundreds (or thousands) of popular songs have been written with the same chords, and we don’t find them boring or overused. In fact, the odds are you didn’t even know this was the case. But is there something inherently appealing about the chords and harmonies that we like, or is it that we’ve simply become so accustomed to them?

The question is not new. It’s been around for centuries. According to legend, the Ancient Greek thinker Pythagoras claimed that all humans like “consonance” — pleasant-sounding combinations of notes — and hate dissonant sounds that stray from these combinations. This approach has been the foundation of music for centuries and it’s probably the core of almost every song you’ve ever heard.

But it may be wrong, and researchers have proven it using unusual gongs.

Mathematics and music

The first step you need to take is to eliminate familiar instruments from the picture. You’re used to things like guitars and pianos so it wouldn’t be possible to assess what’s inherently pleasant and what’s an acquired taste. So, Peter Harrison, from Cambridge’s Faculty of Music, turned to the bonang, an instrument from the Javanese gamelan built from a collection of small gongs.

It’s not just the familiarity of the instrument that’s important, it’s about the type of notes that they create.

Music is essentially audible mathematics and physics. Sounds are vibrations that occur at various frequencies, which we often associate with specific notes. For example, the note “C” is typically associated with a frequency of 261.63 Hz, and the note “A” is commonly set at 440 Hz. An octave, in musical terms, refers to the interval between one musical pitch and another with double its frequency. Therefore, moving up one octave from a “C” note at 261.63 Hz would bring you to the next “C” at approximately 523.25 Hz, which is double the frequency of the starting note.

This type of mathematical relationship between notes basically decides the sounds that we like. However, the consonance of instruments like the bonang doesn’t fit neatly within the cracks of the scale traditionally used in Western music.

The bonang produces tones that contain frequencies not aligned with the fixed pitches of the Western musical scale. These tones can create harmonies that are perceived as consonant within the context of Javanese music but may not correspond to the intervals found in Western tempered scales.

“The shape of some percussion instruments means that when you hit them, and they resonate, their frequency components don’t respect those traditional mathematical relationships. That’s when we find interesting things happening,” says Harrison.

We like some imperfections

Conventional wisdom (Pythagoras’ wisdom) says that we shouldn’t really like this. But when researchers asked 4,000 people from the US and South Korea to rate the pleasantness of bonang notes and chords, they were able to appreciate newer and unfamiliar harmonies. These are not trained musicians or anyone who would be familiar with the instrument, so the findings should be relevant for the general population.

Notably, the study suggests that its participants appreciated the new consonances of the bonang’s tones instinctively. The bonang consonances that were well-received fit neatly into the musical scales commonly used in the Indonesian culture from which the instrument comes. These scales don’t have an equivalent in most instruments we’re familiar with in the west — and yet participants liked it.

“Western research has focused so much on familiar orchestral instruments, but other musical cultures use instruments that, because of their shape and physics, are what we would call ‘inharmonic’.”

Still, it gets even more interesting: researchers found a slight preference towards imperfection or “inharmonicity”.

There’s a lot of music we haven’t even explored yet

Remarkably, based on these findings, it seems we’ve been needlessly limiting ourselves when it comes to musical creation.

“Music creation is all about exploring the creative possibilities of a given set of qualities,” says Harrison. For instance, artists explore what types of songs they could play on a flute or on a guitar. But we might have been limiting ourselves to only a part of the music we can make. Mistakenly, it seems, we assumed we wouldn’t like other sounds.

“Our findings suggest that if you use different instruments, you can unlock a whole new harmonic language that people intuitively appreciate, they don’t need to study it to appreciate it. A lot of experimental music in the last 100 years of Western classical music has been quite hard for listeners because it involves highly abstract structures that are hard to enjoy. In contrast, psychological findings like ours can help stimulate new music that listeners intuitively enjoy.”

The key to exploring new musical avenues is to use the right instruments. You can’t go and play a traditional bonang song on a piano because it doesn’t have the same types of notes. So, to venture into new musical territory, we need the right instruments.

Expanding the orchestra

“Quite a lot of pop music now tries to marry Western harmony with local melodies from the Middle East, India, and other parts of the world. That can be more or less successful, but one problem is that notes can sound dissonant if you play them with Western instruments.

“Musicians and producers might be able to make that marriage work better if they took account of our findings and considered changing the ‘timbre’, the tone quality, by using specially chosen real or synthesised instruments. Then they really might get the best of both worlds: harmony and local scale systems.”

Now, Harrison and colleagues want to expand their study to also look at other instruments from more cultures. They hope that in this process, they can gain more insights into “inharmonic” instruments that challenge the traditional Western concepts of harmony and consonance. By engaging with musicians who use “inharmonic” instruments, Harrison’s team aims to delve deeper into the understanding of musical appreciation across different cultures.

This exploration not only broadens the scope of their research but also highlights the vast, uncharted territories of musical expression.

Journal Reference: R Marjieh, P M C Harrison, H Lee, F Deligiannaki, and N Jacoby, ‘Timbral effects on consonance disentangle psychoacoustic mechanisms and suggest perceptual origins for musical scales’, Nature Communications (2024). DOI: 10.1038/s41467-024-45812-z